A recent study by the Centers for Disease Control found perchlorate, a hazardous chemical in rocket fuel, has been found at potentially dangerous levels in powdered infant formula.

Perchlorate exposure can damage the thyroid, which can hinder brain development among infants. In the new study, scientists tested 15 brands of infant formula and found perchlorate in all of them.

The formulas with the highest perchlorate levels are the most popular among consumers. The most contaminated brands were lactose-based as opposed to soy-based and accounted for 87% of the infant formulas on sale in 2000.

The chemical is also found in the drinking water sources of at least 26 states and two territories around the country. When perchlorate-contaminated powdered formula is mixed with water that is also contaminated, the final product can be particularly harmful to babies.

According to Grist, the CDC study found that, hypothetically, 54% of infants consuming the perchlorate-contaminated formula would exceed EPA’s reference dose, if the formula were mixed with water containing perchlorate at 4 ppb.

In a statement sent to reporters last night, Sen. Barbara Boxer, chair of the Environment and Public Works committee, said the study prompted her to ask the Food and Drug Administration to inform the public “how best to protect children from perchlorate.” As she has done in the past, Boxer called on the EPA to “overrule the Bush Administration’s policy which was to walk away from setting a safe drinking water standard for perchlorate in our water supply.”